Burglar-alarm



(No Model.)

S. E. GARR.

BURGLAR ALARM.

Patented Apr. 13, 1886.

UNITED STATES PATENT il@ F FICE,

BURGLAR-ALARNI.

SPECIFICATION forming part of Letters Patent No. 339,854, dated April 13, 1886. Application filed February 8, 1886. Serial No. 191,208. (No model.)

To all whom it may concern:

Be it known that I, SPENCER E. CARR, aeitizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Burglar-Alarms, of which the following is a specification.

My invention relates to that class of burglaralarms in which a drop-block carrying a cartridge and firing-pin is supported adjacent to a door, so that when the door is opened the block will be allowed to fall and the cartridge exploded.

My improvements comprise a combined thumb screw and pin for supporting the dropblock and the method ofconstructingsaid dropblock and combining the firing-pin therewith, so that the manufacture and fitting together of the parts is simplifiethand the cost of the de vice reduced to a minimum.

In the accompanying drawings, Figurel is a perspective view, partly in section, showing the application of my improved burglar-alarm to a door and door-frame; Fig. 2, a sectional view, partly in elevation, and on a larger scale than Fig. l; Fig. 3, a perspective view of the combined thumb-screw and supporting-pin forming one of the features of the invention; Fig. 4, a perspective view of' the firing-pin forming part of the device; Fig. 5. a sectional plan on the line l 2, Fig. 2; and Fig. 6, a sectional view showing a modification of my invention.

A represents part of a door, and B part of the door-frame, into which, at a point just above the upper edge of the door, is screwed a threaded pin, a, having an enlarged and flattened head, b, so that it forms a thumbscrew which canv be readily manipulated. From the head b projects a pin, d, which is adapted to an eye, e, at the upper end of a block, D, the latter having a transverse recess, f, with which communicates a vertical opening, g, intended for the reception of a cartridge, x, as shown in Fig. 2, this opening being enlarged in diameter at the lower end for the reception of a firing-pin, F, which is free to move vertically within the opening to an extent limited by a transverse pin, h, carried by the block D, the inner end of said pin projecting into agroove, z', in the firingpin, which groove is of somewhat greater Width than the diameter of the pin. rlhe firing-pin F has an enlarged head, m, at the bottoni, and when, on the opening of the door A, the block D is thrust from the pin d and allowed to fall, the head of the tiringpin strikes the oor and the cartridge is thereby brought into forcible contact with and eX ploded by a teat, a, on the firing-piu.

In order to permit the withdrawal of the firing-pin when it is desired to remove the shell of an exploded cartridge and the insertion of a new cartridge in its place, the flange s of the firing-pin above the groove t' has a notch, t, at one side, for the passage of the pin h, so that when it is desired to withdraw the pin F the latter is turned until the notch is in line with said pin Iz, a like adjustment ofthe pin being effected when the latter is reintroduced, and the pin being turned when the flange .s has passed the pin h, so that the latter will engage with the liange and retain the pin F-in place.

The grooved portion ofthe pin F is preferably provided with a stoplug, to, which, by Contact with the pin li, serves to limit the turning movement of' the pin F when the latter has reached the position in which it should be allowed to remain-that is to say, the position in which the notch t of the iiange s is farthest removed from the retaining-pin 7i.

By constructing the block and tiring-pin iu the manner set forth, I am enabled to simplify the device and reduce the cost of the same to a minimum, as no threading or other expensive machine-fitting of the parts is required. The pin h may be so fitted to the block that it can be moved laterally, in which case the notched flange s of' the firing-pin will be unnecessary, the inner end of the pin h being projected into the recess 'i of the firing-pin after the latter has been inserted into the block.

It' desired, the exploding device may be in the form of a cap, embracing the lower portion of the block D and having a pin, h, supported by a flange, s, on the block, said flange having a notch, t, for the passagfl of the pin, as shown in Fig. 6.

I claim as my invention- 1. The withindescribed holder for a detonating burgluralarm, said holder consisting of a screw-pin, a, having a flattened head., b,With projecting pin d, all substantially as specified.

2. The combination of the block D, having IOO an opening for the reception of a cartridge, an exploding device, an annular ange formed on one of said parts and having a notch at oneside and a retaining-pin on the other part for engagement with said notched annular flange,

i all substantially as specified.

3. The combination of the block D, having an opening foi the reception of a cartridge,the internally-projecting pin 11 and a ring-pin adapted to the opening in the block and having a recess, i, for the reception of the retaining-pin, said recess being of greater Width than the diameterl of the pin, all substantially as specified.

4. The combination of the` block D, having x 5 an opening for the reception of a cartridge,the internally-projecting retaining-pin, and a firing-pin having a notched ange, s, and recess fi, for the reception of the retaining-pin,

all substantially as specified. zo In testimony whereofI have signed my name to this specification in the presence of two subscribing witnesses.

` SPENCER E. CARB.

Witnesses:

WILLIAM F. DAVIS,

HARRY SMITH. 

